How to Clean Polycarbonate Roof

How to clean polycarbonate sheets

In this article, we discuss in detail on how to clean polycarbonate roof, it is written to supplement the Handling, Storage & Cleaning Polycarbonate Sheets article which is also in the FAQ section.

As one of the lightest (less than half the weight of glass), strongest (250 times stronger than glass, 10 times more than standard PVC FRP, shatter proof, and considered the most agile and durable light transmitting glazing material; it is imperative to properly maintain the polycarbonate roofing sheet so that it retains all its magnificent properties over long periods of time.

It is only natural that any exterior surface is subject to weathering and rigors of the outdoors, to which polycarbonate sheets, like all outdoor building materials, are not immune to. Chain breaking by polymer weathering causes increasing embrittlement of plastic items, which eventually causes them to break apart. Fragmentation then continues until eventually microplastics are formed. As the particle sizes get smaller, so their combined surface area increases, and as a result, is the yellowing and cracking of polycarbonate sheets we see.

As the years go by and the 4 seasons come and go, and although the difference between seasons are not as distinct in certain areas of the world, degradation occurs in the environment mainly due to the effects of UV-light, oxygen, water and pollutants, which is often generalized as polymer weathering – the end result could see the emergence of moss, mould, mildew, algae and lichen on the polycarbonate.

The moss, mould, mildew, algae and lichen come solely from the environment and the air we breathe in, circulated by the wind and effects shaded and damp surfaces in particular, which are perfect hotbeds for them to grow and spread.

It is not the end of the world though, as with all other outdoor building materials, regular cleaning of your polycarbonate roof with a soft sponge, warm soapy water, and then dried out with soft, lint-free cloth will keep your polycarbonate roofing sheets looking as good as new.  For areas which have been neglected and has accumulated layers of moss, mould, mildew & lichen, more specific treatment are to be implemented, especially when it comes to lichen, as it may damage the polycarbonate surface and UV protective coating in the long term.

How to Clean Polycarbonate Roof

Cleaning lichen, black molds, or any stubborn, unwanted, hard to remove substrates on polycarbonate roof sheets may require a bit more effort than routine cleaning. Here’s a step-by-step guide on how to clean polycarbonate roof sheets:

Materials you’ll need :

  • Soft brush with gentle bristles
  • Mild soap or dishwashing detergent
  • Water
  • Soft sponge or microfiber cloth
  • Plastic scraper or spatula
  • Sodium Hypochlorite (Bleach) based outdoor cleaners, with additives to assist the product to stick, spread and penetrate the surface.
    For ease of demonstration, we’ll use the abbreviation, SH from hereon.
  • Lint-free towels or paper towels

Steps :

  1. Remove Loose Debris :
    Begin by gently removing any loose dirt or debris from the surface of the polycarbonate sheet using a soft brush or a gentle stream of water.
  2. Prepare a Cleaning Solution :
    Mix a solution of mild soap or dishwashing detergent with water. Use a mixture of one or two teaspoons of soap per gallon of water.
  3. Apply the Cleaning Solution :
    Apply the soapy water solution to the lichen-covered areas using a soft sponge or microfiber cloth. Allow it to sit for a few minutes to help loosen the lichen.
  4. Scrub with Soft Brush :
    Gently scrub the lichen-covered areas with a soft brush. Be careful not to use excessive force to avoid scratching the polycarbonate surface.
  5. Use a Plastic Scraper :
    If the substrates are still stubborn, you can use a plastic scraper or spatula to carefully scrape off the loosened substrate. Hold the scraper at a low angle to avoid scratching.
  6. Apply SH :
    For persistent substrate stains, you can apply white vinegar directly to the affected areas. Allow it to sit for a few minutes before gently scrubbing with a soft brush.
  7. Rinse Thoroughly :
    Rinse the polycarbonate roofing sheet thoroughly with clean water to remove any soap or SH residue. Use a hose or a bucket of clean water for this step.
  8. Dry the Surface :
    Wipe the polycarbonate sheet dry with lint-free towels or paper towels. Avoid using abrasive materials that could scratch the surface.


  • Be patient, as removing stubborn subtrates may require multiple cleaning attempts.
  • Avoid using harsh chemicals, abrasives, or high-pressure washers, as they can damage the polycarbonate surface.
  • Clean the polycarbonate sheets on a cloudy day or in the shade to prevent cleaning solutions from drying too quickly.
  • If the substrates persist after following these steps, you may want to consult with a professional for additional advice or consider specialized cleaners designed for removing organic growth from surfaces.